Betta splendens, the fighting fish. They are relatively peaceful with otehr fish, but do not like others of their own species. They build a nest of mucus covered air bubbles for their eggs to be laid into, the male tends the eggs in the nest until they hatch in a couple of days.
I didn't know that...
@jorasiro pleased to have been able to help you find out something new.
There are a few others in the family which also bubble nest, whilst the remainder are paternal mouthbrooders, that is, the male holds the eggs in his mouth for a few weeks prior to hatching.